Just like with {spoiler} and {spoiler=}, actually.
Otherwise, I reckon this is a great idea! Well done!
My own tag suggestions would be links to all of the forums, so instead of RP, have II, NS etc. Then maybe some tags for the really really big inter-regional alliances, although I suppose much of that would come under defender/raider friendly. Alternatively a 'private' tag, if your region is just for you and your mates, maybe linked to password-protection.
Finally, a few tests of my own: